prometheusreceiver: add trim_metric_suffixes configuration option

.chloggen/prometheus-receiver-normalization-config.yaml

@@ -0,0 +1,23 @@
+# Use this changelog template to create an entry for release notes.
+# If your change doesn't affect end users, such as a test fix or a tooling change,
+# you should instead start your pull request title with [chore] or use the "Skip Changelog" label.
+
+# One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix'
+change_type: 'breaking'
+
+# The name of the component, or a single word describing the area of concern, (e.g. filelogreceiver)
+component: prometheusreceiver
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: "Add the `trim_metric_suffixes` configuration option to allow enable metric suffix trimming."
+
+# Mandatory: One or more tracking issues related to the change. You can use the PR number here if no issue exists.
+issues: [21743, 8950]
+
+# (Optional) One or more lines of additional information to render under the primary note.
+# These lines will be padded with 2 spaces and then inserted directly into the document.
+# Use pipe (|) for multiline entries.
+subtext: | 
+  When enabled, suffixes for unit and type are trimmed from metric names. 
+  If you previously enabled the `pkg.translator.prometheus.NormalizeName` 
+  feature gate, you will need to enable this option to have suffixes trimmed.

pkg/translator/prometheus/normalize_name.go

@@ -71,7 +71,7 @@ var perUnitMap = map[string]string{
 	"y":  "year",
 }
 
-var NormalizeNameGate = featuregate.GlobalRegistry().MustRegister(
+var normalizeNameGate = featuregate.GlobalRegistry().MustRegister(
 	"pkg.translator.prometheus.NormalizeName",
 	featuregate.StageAlpha,
 	featuregate.WithRegisterDescription("Controls whether metrics names are automatically normalized to follow Prometheus naming convention"),
@@ -90,7 +90,7 @@ func BuildPromCompliantName(metric pmetric.Metric, namespace string) string {
 	var metricName string
 
 	// Full normalization following standard Prometheus naming conventions
-	if NormalizeNameGate.IsEnabled() {
+	if normalizeNameGate.IsEnabled() {
 		return normalizeName(metric, namespace)
 	}
 
@@ -182,10 +182,6 @@ func normalizeName(metric pmetric.Metric, namespace string) string {
 //
 // [OpenTelemetry specs]: https://github.com/open-telemetry/opentelemetry-specification/blob/main/specification/metrics/data-model.md#metric-metadata
 func TrimPromSuffixes(promName string, metricType pmetric.MetricType, unit string) string {
-	if !NormalizeNameGate.IsEnabled() {
-		return promName
-	}
-
 	nameTokens := strings.Split(promName, "_")
 	if len(nameTokens) == 1 {
 		return promName

pkg/translator/prometheus/normalize_name_test.go

@@ -138,8 +138,6 @@ func TestOtelReceivers(t *testing.T) {
 }
 
 func TestTrimPromSuffixes(t *testing.T) {
-	defer testutil.SetFeatureGateForTest(t, NormalizeNameGate, true)()
-
 	assert.Equal(t, "active_directory_ds_replication_network_io", TrimPromSuffixes("active_directory_ds_replication_network_io_bytes_total", pmetric.MetricTypeSum, "bytes"))
 	assert.Equal(t, "active_directory_ds_name_cache_hit_rate", TrimPromSuffixes("active_directory_ds_name_cache_hit_rate_percent", pmetric.MetricTypeGauge, "percent"))
 	assert.Equal(t, "active_directory_ds_ldap_bind_last_successful_time", TrimPromSuffixes("active_directory_ds_ldap_bind_last_successful_time_milliseconds", pmetric.MetricTypeGauge, "milliseconds"))
@@ -170,12 +168,6 @@ func TestTrimPromSuffixes(t *testing.T) {
 
 }
 
-func TestTrimPromSuffixesWithFeatureGateDisabled(t *testing.T) {
-	defer testutil.SetFeatureGateForTest(t, NormalizeNameGate, false)()
-	assert.Equal(t, "apache_current_connections", TrimPromSuffixes("apache_current_connections", pmetric.MetricTypeGauge, "connections"))
-	assert.Equal(t, "apache_requests_total", TrimPromSuffixes("apache_requests_total", pmetric.MetricTypeSum, "1"))
-}
-
 func TestNamespace(t *testing.T) {
 	require.Equal(t, "space_test", normalizeName(createGauge("test", ""), "space"))
 	require.Equal(t, "space_test", normalizeName(createGauge("#test", ""), "space"))
@@ -220,7 +212,7 @@ func TestRemoveItem(t *testing.T) {
 
 func TestBuildPromCompliantNameWithNormalize(t *testing.T) {
 
-	defer testutil.SetFeatureGateForTest(t, NormalizeNameGate, true)()
+	defer testutil.SetFeatureGateForTest(t, normalizeNameGate, true)()
 	require.Equal(t, "system_io_bytes_total", BuildPromCompliantName(createCounter("system.io", "By"), ""))
 	require.Equal(t, "system_network_io_bytes_total", BuildPromCompliantName(createCounter("network.io", "By"), "system"))
 	require.Equal(t, "_3_14_digits", BuildPromCompliantName(createGauge("3.14 digits", ""), ""))
@@ -232,7 +224,7 @@ func TestBuildPromCompliantNameWithNormalize(t *testing.T) {
 
 func TestBuildPromCompliantNameWithoutNormalize(t *testing.T) {
 
-	defer testutil.SetFeatureGateForTest(t, NormalizeNameGate, false)()
+	defer testutil.SetFeatureGateForTest(t, normalizeNameGate, false)()
 	require.Equal(t, "system_io", BuildPromCompliantName(createCounter("system.io", "By"), ""))
 	require.Equal(t, "system_network_io", BuildPromCompliantName(createCounter("network.io", "By"), "system"))
 	require.Equal(t, "system_network_I_O", BuildPromCompliantName(createCounter("network (I/O)", "By"), "system"))

receiver/prometheusreceiver/README.md

@@ -102,6 +102,28 @@ receivers:
               action: keep
 ```
 
+The prometheus receiver also supports additional top-level options:
+
+- **trim_metric_suffixes**: [**Experimental**] When set to true, this enables trimming unit and some counter type suffixes from metric names. For example, it would cause `singing_duration_seconds_total` to be trimmed to `singing_duration`. This can be useful when trying to restore the original metric names used in OpenTelemetry instrumentation. Defaults to false.
+- **use_start_time_metric**: When set to true, this enables retrieving the start time of all counter metrics from the process_start_time_seconds metric. This is only correct if all counters on that endpoint started after the process start time, and the process is the only actor exporting the metric after the process started. It should not be used in "exporters" which export counters that may have started before the process itself. Use only if you know what you are doing, as this may result in incorrect rate calculations. Defaults to false.
+- **start_time_metric_regex**: The regular expression for the start time metric, and is only applied when use_start_time_metric is enabled.  Defaults to process_start_time_seconds.
+
+For example,
+
+```yaml
+receivers:
+    prometheus:
+      trim_metric_suffixes: true
+      use_start_time_metric: true
+      start_time_metric_regex: foo_bar_.*
+      config:
+        scrape_configs:
+          - job_name: 'otel-collector'
+            scrape_interval: 5s
+            static_configs:
+              - targets: ['0.0.0.0:8888']
+```
+
 ## OpenTelemetry Operator 
 Additional to this static job definitions this receiver allows to query a list of jobs from the 
 OpenTelemetryOperators TargetAllocator or a compatible endpoint. 

receiver/prometheusreceiver/config.go

@@ -32,9 +32,10 @@ const (
 
 // Config defines configuration for Prometheus receiver.
 type Config struct {
-	PrometheusConfig *promconfig.Config `mapstructure:"-"`
-	BufferPeriod     time.Duration      `mapstructure:"buffer_period"`
-	BufferCount      int                `mapstructure:"buffer_count"`
+	PrometheusConfig   *promconfig.Config `mapstructure:"-"`
+	TrimMetricSuffixes bool               `mapstructure:"trim_metric_suffixes"`
+	BufferPeriod       time.Duration      `mapstructure:"buffer_period"`
+	BufferCount        int                `mapstructure:"buffer_count"`
 	// UseStartTimeMetric enables retrieving the start time of all counter metrics
 	// from the process_start_time_seconds metric. This is only correct if all counters on that endpoint
 	// started after the process start time, and the process is the only actor exporting the metric after

receiver/prometheusreceiver/config_test.go

@@ -40,6 +40,7 @@ func TestLoadConfig(t *testing.T) {
 	assert.Equal(t, r1.PrometheusConfig.ScrapeConfigs[0].JobName, "demo")
 	assert.Equal(t, time.Duration(r1.PrometheusConfig.ScrapeConfigs[0].ScrapeInterval), 5*time.Second)
 	assert.Equal(t, r1.UseStartTimeMetric, true)
+	assert.Equal(t, r1.TrimMetricSuffixes, true)
 	assert.Equal(t, r1.StartTimeMetricRegex, "^(.+_)*process_start_time_seconds$")
 
 	assert.Equal(t, "http://my-targetallocator-service", r1.TargetAllocator.Endpoint)

receiver/prometheusreceiver/go.mod

@@ -8,7 +8,6 @@ require (
 	github.com/golang/snappy v0.0.4
 	github.com/mitchellh/hashstructure/v2 v2.0.2
 	github.com/open-telemetry/opentelemetry-collector-contrib/exporter/prometheusremotewriteexporter v0.81.0
-	github.com/open-telemetry/opentelemetry-collector-contrib/internal/common v0.81.0
 	github.com/open-telemetry/opentelemetry-collector-contrib/pkg/pdatautil v0.81.0
 	github.com/open-telemetry/opentelemetry-collector-contrib/pkg/translator/prometheus v0.81.0
 	github.com/prometheus/common v0.44.0

receiver/prometheusreceiver/internal/appendable.go

@@ -20,6 +20,7 @@ type appendable struct {
 	sink                 consumer.Metrics
 	metricAdjuster       MetricsAdjuster
 	useStartTimeMetric   bool
+	trimSuffixes         bool
 	startTimeMetricRegex *regexp.Regexp
 	externalLabels       labels.Labels
 
@@ -35,7 +36,8 @@ func NewAppendable(
 	useStartTimeMetric bool,
 	startTimeMetricRegex *regexp.Regexp,
 	useCreatedMetric bool,
-	externalLabels labels.Labels) (storage.Appendable, error) {
+	externalLabels labels.Labels,
+	trimSuffixes bool) (storage.Appendable, error) {
 	var metricAdjuster MetricsAdjuster
 	if !useStartTimeMetric {
 		metricAdjuster = NewInitialPointAdjuster(set.Logger, gcInterval, useCreatedMetric)
@@ -56,9 +58,10 @@ func NewAppendable(
 		startTimeMetricRegex: startTimeMetricRegex,
 		externalLabels:       externalLabels,
 		obsrecv:              obsrecv,
+		trimSuffixes:         trimSuffixes,
 	}, nil
 }
 
 func (o *appendable) Appender(ctx context.Context) storage.Appender {
-	return newTransaction(ctx, o.metricAdjuster, o.sink, o.externalLabels, o.settings, o.obsrecv)
+	return newTransaction(ctx, o.metricAdjuster, o.sink, o.externalLabels, o.settings, o.obsrecv, o.trimSuffixes)
 }

receiver/prometheusreceiver/internal/metricfamily.go

@@ -301,10 +301,14 @@ func (mf *metricFamily) addSeries(seriesRef uint64, metricName string, ls labels
 	return nil
 }
 
-func (mf *metricFamily) appendMetric(metrics pmetric.MetricSlice) {
+func (mf *metricFamily) appendMetric(metrics pmetric.MetricSlice, trimSuffixes bool) {
 	metric := pmetric.NewMetric()
-	// Trims type's and unit's suffixes from metric name
-	metric.SetName(prometheus.TrimPromSuffixes(mf.name, mf.mtype, mf.metadata.Unit))
+	// Trims type and unit suffixes from metric name
+	name := mf.name
+	if trimSuffixes {
+		name = prometheus.TrimPromSuffixes(name, mf.mtype, mf.metadata.Unit)
+	}
+	metric.SetName(name)
 	metric.SetDescription(mf.metadata.Help)
 	metric.SetUnit(mf.metadata.Unit)
 

receiver/prometheusreceiver/internal/metricfamily_test.go

@@ -249,7 +249,7 @@ func TestMetricGroupData_toDistributionUnitTest(t *testing.T) {
 			require.Len(t, mp.groups, 1)
 
 			sl := pmetric.NewMetricSlice()
-			mp.appendMetric(sl)
+			mp.appendMetric(sl, false)
 
 			require.Equal(t, 1, sl.Len(), "Exactly one metric expected")
 			metric := sl.At(0)
@@ -537,7 +537,7 @@ func TestMetricGroupData_toSummaryUnitTest(t *testing.T) {
 			require.Len(t, mp.groups, 1)
 
 			sl := pmetric.NewMetricSlice()
-			mp.appendMetric(sl)
+			mp.appendMetric(sl, false)
 
 			require.Equal(t, 1, sl.Len(), "Exactly one metric expected")
 			metric := sl.At(0)
@@ -643,7 +643,7 @@ func TestMetricGroupData_toNumberDataUnitTest(t *testing.T) {
 			require.Len(t, mp.groups, 1)
 
 			sl := pmetric.NewMetricSlice()
-			mp.appendMetric(sl)
+			mp.appendMetric(sl, false)
 
 			require.Equal(t, 1, sl.Len(), "Exactly one metric expected")
 			metric := sl.At(0)

receiver/prometheusreceiver/internal/transaction.go

@@ -33,6 +33,7 @@ const (
 
 type transaction struct {
 	isNew          bool
+	trimSuffixes   bool
 	ctx            context.Context
 	families       map[string]*metricFamily
 	mc             scrape.MetricMetadataStore
@@ -53,11 +54,13 @@ func newTransaction(
 	sink consumer.Metrics,
 	externalLabels labels.Labels,
 	settings receiver.CreateSettings,
-	obsrecv *obsreport.Receiver) *transaction {
+	obsrecv *obsreport.Receiver,
+	trimSuffixes bool) *transaction {
 	return &transaction{
 		ctx:            ctx,
 		families:       make(map[string]*metricFamily),
 		isNew:          true,
+		trimSuffixes:   trimSuffixes,
 		sink:           sink,
 		metricAdjuster: metricAdjuster,
 		externalLabels: externalLabels,
@@ -200,7 +203,7 @@ func (t *transaction) getMetrics(resource pcommon.Resource) (pmetric.Metrics, er
 	metrics := ils.Metrics()
 
 	for _, mf := range t.families {
-		mf.appendMetric(metrics)
+		mf.appendMetric(metrics, t.trimSuffixes)
 	}
 
 	return md, nil